Franklin g



Feb. 3, 1931. HOBART 1,790,922

FLUID PRESSURE EQUALIZER Filed Sept. 28, 1925 INVENTOR ATTORNEY Patented Feb. 3, 1931 UNITED STATES PATENT OFFICE FRANKLIN G. HOBART, OF BELOIT, WISCONSIN, ASSIGNOR TO FAIRBANKS, MORSE &

i 00., OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS FLUID-PRESSURE EQUALIZER Application filed September 28, 1925. Serial No. 59,155.

My invention relates to improvements in fluid pressure equalizers and more particularly to improvements in pressure equalizers for fluid pumps.

The object of my invention is to provide such a device which is simple and positive in its operation, economical in construction and which provides great ease of assembly.

Another object of my invention is to provide a device which will. act as a pressure equalizer for a pump and also as a pressure relief valve at such times when the discharge pressure of the pump exceeds certain predetermined maximum values.

Another object of my invention is to provide a device which will act as a combined pressure equalizer and pressure relief valve for a pump and which will also provide means for combining the air and vacuum chambers in the pump.

Another object of my invention is to provide means for preventing the air chamber in the pump from becoming water-logged.

Another object of my invention is to provide a pressure relief valve for a pump which is simple and positive in its operation and which, at the same time,"will afford means for equalizing the discharge pressure of the ump.

Further objects and advantages of my invention will appear from the following draw-- ings and description thereof.

Although my invention consists largely in the construction and arrangement of parts hereinafter described and particularly point- 1 ed out in the claims, yet I do not limit my invention to the precise form construction or arrangement of parts shown or the several parts thereof, inasmuch as various alterations may be made without changing the scope of my invention.

In the drawings Fig. 1 is a sectional elevation of an approved form of my invention and Fig. 2 is a sectional elevation of a modified form of my invention.

In the drawings 5 designates the cylinder of a pump which may be of any suitable type,

located in the casing 6 and having a suction chamber 7 with suction valves 8, which may be of any suitable type, opening into pulsapump.

tion chamber 4. Cylinder 5 is provided with forming a chamber 15. It will be understood, however, that this chamber may be attached .to the pump, or to the discharge thereof, in

any suitable manner and at any place. 16

. designates a cylinder preferably having one end 17 in communication with the discharge chamber 11 of the pump and the other end 18 preferably in communication with the chamber-15. Piston 19 preferably operates in cylinder 16 against the pressure of a spring 20 which may be attached to the cover 21 of chamber 15, as shown. Openings 22 are preferably formed in the wall of cylinder 16 outside of'the discharge chamber 11. The conduit 23 may be connected between the chamber 15 and the suction chamber 7 of the The operation of the device is as follows The discharge pressure in the discharge chamber 11 acts directlyupon the piston 19 and against the pressure of the spring 20 so that when the pump is in operation the -pis ton 19 will havea reciprocatory motion in the cy1inder16, thereby forming an expansible chamber in which this-discharge pressure may act and thus serving to equalize the pressure impulse of the pump and givinga moreequal dischargeflow. If, for any reason, the discharge pressure should become too high, such as would be caused, for example, by obstruction of the outlet 13 or of any of the fittings connected thereto, the pressure on the piston 19 will force the same up into the cylinder 16 past the openings 22 and communication is thereupon established between the discharge chamber 11 and the chamber 15 whereby the excess pressure may find an outlet. It is thus evident that this i device may be made to act as a pressure relief valve for the pump. By connecting the con- 1 pump so that by this means I have combined the air and vacuum chambers of the pump.

It is evident that my device maybe attached anywhere in the discharge of the pump, it only being necessary that the piston 19 be in communication with the discharge pressure of the pump, and it is also evident that the end 18 of the cylinder 16 may be in communication with the atmosphere rather than with the chamber 15, as shown. In case the cylinder 16 has its end 18 in communication with the atmosphere, the discharge from the openings22 may be taken care of in any suitable manner. In the particular arrangement shown it is'evident that the discharge from these openings will be carried directly back to the suction of the pump, thus avoiding any leakage.

In the modified form shown in Fig. 2 I show the conduit -23'- replaced by a cored passage 24 in the casting 12 and in communication, by means of opening 25, with a passage 26 in the casting 6 which communicates directly with the suction chamber 7. This passage 24 is preferably in communication with chamber 15, as by means of openings 27 in flange 28 which preferably supports cylinder 16. Openings 22 communicate directly with this passage 24 and it will be seen that by this construction I have elimi nated the conduit 23 and have secured a more and adapted thereby as a vacuum chamber for said pump,

2. In combination with a pump, a unitary structure having a single chamber therein, a cylinder in said chamber, and communicating with the pump discharge, and with the pump inlet. said cylinder having'a pressure relief opening therein arranged to relieve excessive pumpdischarge pressures, a spring loaded member in said cylinder adapted to oppose the normal fluid inlet fluctuations and at a predetermined pressure to uncover the pressure relief opening.

3. In a pump, a vacuum chamber, a pressure equalizing device adapted normallyto coact with, and disposed within said chamber, said device bein adapted to relieve excess pressure by flu1d discharge into said vacuum chamber.

4. In a pump, a. pressure equalizing container having one portion in communication with the discharge of the pump and another portion in communication with the suction thereof, and releasing means associated with said container and'adapted to operate at a predetermined pressure, said means being adapted, normally, to equalize pump discharge pressure.

5'. In a pump, a device adapted to equalize discharge pressure, equalize intake suction and relieve excessive pressure; said device comprisin a chamber and a cylinder within said cham er, one portion of said cylinder being in communication with the discharge of said pump and another portion in communication with the suction thereof, and a releasing means associated with said cylinder and adapted to operate at a predetermined pressure, said means being movable responsively to positive and negative pressures within" said chamber.

6. In combination with a pump, a unitary structure comprising a discharge chamber and a suction chamber, a cylinder having one end in communication with the suction chamber, and the other end in communication with the discharge chamber, and having a pressure relief opening; a spring pressed piston adapted to operate in said cylinder to control said relief opening, whereby said discharge chamber and said suction chamber may be placed in communication through said relief opening, upon a predetermined pressure in said discharge chamber; said piston being further adapted, normally to oppose and equalize the discharge pressure from said pump.

FRANKLIN G. HOBART. 

